This wraparound Lithonia Lighting 4-foot-square two-light T8 fluorescent ceiling fixture exudes a high light level suitable for storage rooms, offices, or retail applications. Its hinged design allows easy cleaning and the instant-on ballast eliminates annoying flickering and humming. This fixture features a diffuser with side prisms to control brightness and bottom prisms to reduce lamp images. To help the environment, it is energy efficient, and it can also reduce your energy costs. For surface or stem mounting, it requires a minimum of two single stem hangers. This wraparound light is backed by a 1-year limited manufacturer"s warranty. The bulb is not included.